1. Field of the Invention
The present invention relates to a method of converting two-dimensional (2 D) images which are outputted from VTRs, video cameras and the like and transmitted by CATV (Cable Television) broadcasting and TV broadcasting and the like into three-dimensional (3 D) images.
2. Description of the Prior Art
Most of 3 D image software used in a 3 D display system which has been recently topical is produced particularly for the 3 D display system. Such 3 D image software is generally recorded by picking up a left eye image and a right eye image using two cameras. The left eye image and the right eye image which are recorded on 3 D image software are displayed with they overlapped with each other on one display almost simultaneously. The left eye image and the right eye image which are displayed with they overlapped with each other are separately incident on the left eye and the right eye of a viewer, whereby the viewer recognizes a 3 D image.
A lot of types of 2 D image software currently exist. If a 3 D image can be produced from the 2 D image software, therefore, time and labor required to produce 3 D image software having the same content as that of the existing 2 D image software again from the beginning are conserved.
Consequently, a method of converting 2 D images into 3 D images has been already proposed. Specifically, in the case of a 2 D image in which an object moves from the right to the left against a background is projected, the 2 D image is taken as a right eye image, and an image several fields ahead of the right eye image is taken as a left eye image. Consequently, binocular parallax thus occurs between the left eye image and the right eye image. If both the images are displayed on a screen almost simultaneously, and the left eye image and the right eye image are respectively viewed with the left eye and the right eye of the viewer, therefore, the moving object is recognized as if it jumped out forward from the background.
In the above described method, however, a 3 D image having binocular parallax can be obtained if the original 2 D image is a moving image horizontally moving, while a 3 D image having binocular parallax cannot be obtained if the original 2 D image is a still image.
In some cases, the movement of an object desired to be recognized as if it jumped out of a screen surface is small and the movement of a background is large depending on the content of 2 D image software (a story). For example, consider a case where the background moves from the right to the left. In this case, if the original 2 D image is taken as a left eye image and an image several fields ahead of the left eye image is taken as a right eye image, the background is recognized as if it existed behind the screen surface. As a result, the object whose movement is small is recognized as if it jumped out forward from the background. In this case, however, an image of the object is on the screen surface. Accordingly, the distance from the screen surface to the image of the object recognized by the viewer is zero, whereby an impressive 3 D effect cannot be obtained.
An object of the present invention is to provide a method of converting 2 D images into 3 D images, in which a 3 D image having binocular parallax can be obtained even if the original 2 D image is a still image.
Another object of the present invention is to provide a method of converting 2 D images into 3 D images, in which a 3 D image having an impressive 3 D effect is obtained.
Still another object of the present invention is to provide a method of converting 2 D images into 3 D images, in which an impressive 3 D image is obtained from a 2 D image in which an object does not move and a background moves.
(1) Description of a first method of converting 2 D images into 3 D images according to the present invention
The first method of converting 2 D images into 3 D images is characterized by comprising the step of producing from a 2 D image a first image which forms the basis and a second image obtained by horizontally shifting the first image and taking one of the first image and the second image as a left eye image and taking the other image as a right eye image.
The above described second image is produced by storing the first image in a memory for each horizontal scanning period and adjusting the position where the readout of the image stored in the memory is started to read out the image stored in the memory, for example.
In the first method of converting 2 D images into 3 D images according to the present invention, a 3 D image signal (a left eye image and a right eye image) having binocular parallax is obtained from a 2 D image which is a still image.
(2) Description of a second method of converting 2 D images into 3 D images according to the present invention
The second method of converting 2 D images into 3 D images is characterized by comprising the steps of judging whether a 2 D image is a moving image or a still image, producing from the 2 D image a first image which forms the basis and a second image which is delayed along the time base from the first image and taking one of the first image and the second image as a left eye image and taking the other image as a right eye image when it is judged that the 2 D image is a moving image, and producing from the 2 D image a third image which forms the basis and a fourth image obtained by horizontally shifting the third image and taking one of the third image and the fourth image as a left eye image and taking the other image as a right eye image when it is judged that the 2 D image is a still image.
The judgment whether the 2 D image is a moving image or a still image is made by detecting a vector on the movement of the 2 D image and on the basis of the magnitude of the detected vector. In this case, it is judged that the 2 D image is a still image when a horizontal component of the vector is not more than a predetermined value, and it is judged that the 2 D image is a moving image when the horizontal component of the vector is more than a predetermined value.
The above described second image is produced by storing the first image in the memory and reading out from the memory an image which is delayed by a predetermined number of fields from the first image, for example.
The above described fourth image is produced by storing the third image in the memory for each horizontal scanning period and adjusting the position where the readout of the image stored in the memory is started to read out the image stored in the memory, for example.
In the second method of converting 2 D images into 3 D images according to the present invention, even when the 2 D image signal is a moving image or a still image, a 3 D image signal having binocular parallax is obtained.
(3) Description of a third method of converting 2 D images into 3 D images according to the present invention
The third method of converting 2 D images into 3 D images is characterized by comprising the steps of producing from a 2 D image a first image which forms the basis and a second image which is delayed along the time base from the first image, and producing from the second image a third image obtained by horizontally shifting the second image and taking one of the first image and the third image as a left eye image and taking the other image as a right eye image.
The above described second image is produced by storing the first image in the memory and reading out from the memory an image which is delayed by a predetermined number of fields from the first image, for example.
The above described third image is produced by storing the second image in the memory for each horizontal scanning period and adjusting the position where the readout of the image stored in the memory is started to read out the image stored in the memory, for example.
In the third method of converting 2 D images into 3 D images according to the present invention, it is possible to realize from a 2 D image in which an object does not move and a background moves an impressive 3 D image in which the object and the background are recognized as if the background existed ahead of a screen surface of a display and the object existed ahead of the background.
(4) Description of a fourth method of converting 2 D images into 3 D images according to the present invention
The fourth method of converting 2 D images into 3 D images is characterized by comprising the steps of producing from a 2 D image a first image which forms the basis and a second image which is delayed along the time base from the first image, and producing from the first image a third image obtained by horizontally shifting the first image and taking one of the second image and the third image as a left eye image and taking the other image as a right eye image.
The above described second image is produced by storing the first image in the memory and reading out from the memory an image which is delayed by a predetermined number of fields from the first image, for example.
The above described third image is produced by storing the first image in the memory for each horizontal scanning period and adjusting the position where the readout of the image stored in the memory is started to read out the image stored in the memory.
In the fourth method of converting 2 D images into 3 D images according to the present invention, it is possible to realize from a 2 D image in which an object does not move and a background moves an impressive 3 D image in which the object and the background are recognized as if the background existed ahead of a screen surface of a display and the object ahead of the background.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.